Federal Aviation Administration / Flight Standards District Office; Denver, Colorado
Investigation Docket - National Transportation Safety Board:
Location: Brighton, CO
Accident Number: CEN20CA366
Date & Time: August 27, 2020, 11:55 Local
Registration: N36SC
Aircraft: Backcountry Super Cubs SC-360
Injuries: N/A
Flight Conducted Under: Part 91: General aviation - Instructional
Aircraft and Owner/Operator Information
Aircraft Make: Backcountry Super Cubs
Registration: N36SC
Model/Series: SC-360
Aircraft Category: Airplane
Amateur Built: No
Operator: On file
Operating Certificate(s) Held: None
Operator Designator Code:
Meteorological Information and Flight Plan
Conditions at Accident Site: VMC
Condition of Light: Day
Observation Facility, Elevation:
Observation Time:
Distance from Accident Site:
Temperature/Dew Point:
Lowest Cloud Condition:
Wind Speed/Gusts, Direction: / ,
Lowest Ceiling:
Visibility:
Altimeter Setting:
Type of Flight Plan Filed: None
Departure Point: Brighton, CO (CO12)
Destination: Brighton, CO (CO12)
Wreckage and Impact Information
Crew Injuries:
Aircraft Damage:
Substantial
Passenger Injuries:
Aircraft Fire: None
Ground Injuries: N/A
Aircraft Explosion: None
Total Injuries: N/A
Latitude, Longitude: 39.983333,-104.704444 (est)
Operating Certificates Held: None?
ReplyDeleteI believe as did the PIC, he was in full control after "multiple flights, 50 landings over a couple of days," and the instructor was out of place, otherwise he should have taken control from the back seat!
ReplyDeleteNOT A PILOT and was NOT THERE.. BUT "CUT POWER CUT POWER" sounds like cut power NOT apply brakes....but this is all history now Very nice to see no one was seriously injured.
DeleteIt was just a matter of time before those ridiculous unnecessarily long gear legs showed what they're capable of...
ReplyDeleteWell that extreme modified gear is for landing in extreme off airport landings like in bush Alaska on a rocky creek bed. There's nothing wrong with that design, but like a jacked up 4x4 meant for off road, it will not handle well in an emergency situation on a prepared road (read: easier to flip over). I don't see what's hard to comprehend about that.
DeleteIt's called 'the point of diminishing returns'.
DeleteSuper Cub gear legs are 3" over and some times 3" forward of the stock location, maximum, for a reason. The reason raising the gear length stopped at 3" is because that's about the sweet spot for clearance while not upsetting the tipping point, as is shown in this example. The original builder built his own gear legs for this plane, it was at least 6" over as I recall. Even with an 81" prop, those gear legs and 31" or 33" tires are completely unnecessary for clearance and with stock oleos there's zero rough field benefit from useless long sticks. You can do an online search for 'Super Chub' and see this plane sitting on the gear with a decent sized prop and the overkill is obvious, the prop is miles from the ground. When a Cub starts coming up on the nose when you're on the brakes it's gentle and predictable and controllable. When it's on 5 feet or whatever of gear legs and wheels, when that tail comes up, it's too late to do anything and it's going to end like this. There are also a couple videos online of Cubs experimenting with similar length gear, and it's really obvious why everyone went back down to +3". As for that plane landing in extreme off airport rocky creek beds- that has never happened and that will never happen. With stock oleos and those long sticks that thing would fold like a cheap suit. Much like it did here. His best path forward would be to get a pair of +3 +3 gear legs from Airframes Alaska and a pair of Acme shocks.
Dumb shit blames it on the instructor. "cut power, cut power" means cut power not hit the brakes hard enough to tip us over.
ReplyDelete